Topical compositions including propolis show improved effectiveness over compositions such as salicylic acid for the treatment of warts.
Warts are a widespread medical problem that cause pain and discomfort, and may lead to complications if untreated or improperly treated. Warts are benign growths of the skin caused by a virus that involves the epidermis. Five different types of warts are classified by their clinical presentation. (1) Verrucae vulgares are common warts that display hyperkeratosis and may occur anywhere except the genital and mucous membranes and plantar surfaces (soles of the feet); (2) Verrucae planae are flat warts that usually occur on the face, trunk and extremities; (3) Verrucae plantares are warts that occur only on the soles of the feet; (4) Condylomata acuminata are venereal warts that occur on the genitals and mucous membranes; (5) premalignant warts (Epidermoldysplasia verruciformis) usually occur on the hands and feet and are rare in occurrence.
Currently, there are no completely successful, treatments for warts. Current treatments of verrucae involve physical destruction of the infected cells. Choice of treatment depends on the location, size, number, type of wart, age and co-operation of the patient. No one treatment modality is uniformally effective or directly antiviral.
Antiwart treatments include cryotherapy with liquid nitrogen, caustics and acids such as salicylic acid, lactic acid and trichloroacetic acid which destroy and peel off infected skin. Retinoic acid has been used topically to treat flat warts. Cantharidin is an extract of the green blister beetle that leads to blistering and focal destruction of the epidermis. Induction of allergic contact dermatitis with dinitrochlorobenzene (DNCB) produces local inflammation to warts on which this chemical has been applied.
Chemotherapeutic agents also employed for venereal warts include topically applied podophyllin resin which is more effective on mucosal surfaces. It is contraindicated in pregnancy and the potency of podophyllin preparations may be highly variable. Purified podophyllotoxin is available having activity that is reproducible in vitro Application of 5-fluorouracil is sometimes used to treat flat warts and Condylomata acuminata. Intralesional bleomycin has also been used but may cause extensive tissue necrosis.
Curettage, electrodesiccation, CO.sub.2, and lasers are also used to treat warts. These treatment modalities are painful, require anesthesia and cause scarring. A new immunomodulator, Imiquimod has recently been used to topically treat genital and perianal warts and is currently under review by the Food and Drug Administration. The ultimate mechanism of this new composition is that it appears to act through the production of cytokines and activation of natural killer cells. According to a recent report, forty percent of the treated immunocompetent patients experienced resolution of their warts compared to the control group (treated with the vehicle alone). Three of sixteen patients who manifested no clinical evidences of warts after treatment developed a recurrence during a ten week follow up period. Subsequent studies of several hundred patients confirm the recurrence rates of 40 to 60%.
Salicylic acid in a topical composition is available for the treatment of warts. In this form, salicylic acid is a keratolytic agent that softens the hyperkeratotic areas by dissolving the intra-cellular matrix and enhancing shedding of scales. This composition is nonspecific, being also used for the treatment of psoriasis and other hyperkeratotic disorders. Unfortunately, application of salicylic acid is not always effective for wart resolution. Many patients with warts become frustrated while using salicylic acid because it is ineffective, forcing those patients to seek medical consultation. This may result in applying physical or surgical agents to alleviate patient distress.
Because no effective treatment for warts without appreciable side effects is yet available, other modalities are needed.